You want to hook up a mo phatt to the mpc to record it, as in record the audio output from the mo phatt to the mpc? Or you want to sequence the mo phatt with the MPC?
If you are trying to do what I am thinking, then here:
xp 10 midi out to mpc midi in.
MPC midi out to mo phatt midi in.
This is assuming the mpc midi out works as midi through.